Silencer



S. OLDBERG oct. 22, 1935.

SILENCER Filed Sept. 24, 1954 I NVE NTOR.

AT )RNEYA Patented Oct. 22, 1935 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to silencers and more particularly to silencersused in connection with gases exhausted from internal combustion engmes.

The silencer of this application is of the triplepass retrovertedpassage type, and has a substantially oval or elliptical outer casingprovided with a row of three parallel through-flow tubes which open intoabsorption spaces around the tubes, these spaces being dened andrelatively isolated by a circular intermediate shell which surrounds thecentral one of the tubes and tangentially en` gages the side walls ofthe casing.

In the preferred embodiment, a central header is provided to reinforcethe silencer and to divide the absorption spaces into isolatedabsorption chambers.

Also in the preferred embodiment, the intermediate shell is provided oneach side with a row of bleeder holes, and these communicate the spaceinside the shell with the separated spaces outside the shell.

Objects and other features of the present invention will be readilyapparent to those skilled in the art upon reference to the followingdetailed description of an embodiment of the same, reference being hadto the appended drawing, which shows this embodiment.

In this drawing,

Figure l is a cross section as if on line I-I of Figure 2; and

Figure 2 is a cross section as if on line 2-2 of Figure 1.

Referring to the drawing, it will be seen that the silencer there shownincludes an imperforate outer casing I of substantially oval orelliptical cross section, in which are disposed in a single row, and inside by side parallel juxtaposition, three, relatively spaced, circular,through-flow, tubes I I, I2, and I4, these being somewhat shorter thanthe outer casing. Centrally disposed within the outer casing andtangentially engaging its side walls and surrounding the central tube II is a circular intermediate shell I5, and the latter provides threerelatively isolated absorption spaces I6, I'I, and I8 around the threetubes. The tubes, throughout substantially their entire area, arecovered with a plurality of minute, outwardly extruded perforations I9communicating the through passages in the tubes with the absorptionspaces therearound.

Expansion chambers 24, at each end, provided by end and inner headers 26and 2'I, at each end,

communicate the tubes to provide a triple pass. retroverted passagethrough-flow silencer.

The shell I is divided into two parts, midway between the ends of thesilencer and a central header 30, like the header 2l, and having flanged5 openings through which pass the three tubes, and disposed between thehalves of shell I5 has a dished portion 3l which seats within the openend of one part of the shell I5, the adjacent end 0f the other partbeing swedged inwardly to fit within the dished portion. Disposed withinthe dished portion 3l is an annulus 33, and all of these parts arewelded to one another at the central header to rigidify and unify theconstruction.

It will be observed that the central header not only rigidifles theentire silencer, but also serves the purpose of providing twice as manyabsorption chambers in each absorption space IB, I'I, and I8 as therewould be were the central header eliminated.

In order to reduce the amount of restriction that may exist in asilencer of the type here shown, the absorption chamber I6 may beconnected to the absorption chambers I'I and I8 through a row of smallbleeder holes on each 25 side of the shell I5. These bleeder holesprovide a double absorption effect for each tube, and it may beconsidered that the entire length of the silencer is provided with adouble absorption system for the through passages. It will also beobserved that this expedient may be utilized in silencers of types otherthan the retroverted passage triple-pass type here shown, the systembeing characterized by the provision of interconnected absorptionchambers along the entire ilow path 35 of the silencer.

Now having described a preferred embodiment of the invention of thisapplication, selected by way of example, reference will be had to thefollowing claims for a determination of the scope of the invention.

What I claim is:

1. A silencer of the retroverted passage type comprising an outer casingof substantially oval cross section, an inner and an end headerprovlding an expansion chamber at each end thereof, means providing aninlet and an outlet therefor, and three parallel through-flow tubesmechanically connecting the chambers and lying in a single row andhaving their axes disposed in substantially al common plane, and havinga multiplicity of perforations therein, a circular intermediatetransversely split shell surrounding the center one of thetubes andtangentially engaging the side walls of the casing to provide a soundwave absorption space in the shell around the center tube and inconjunction with the outer casing a sound wave absorption space aroundeach of the other tubes, a central header through which pass said tubes,and which divides each of said absorption spaces in said shell intolongitudinally isolated absorption spaces, the central header having acentral dished portion seated within the end of onc of the parts of theshell and seating the end o! the other part of the shell.

2. A silencer o! the retroverted passage type comprising an outer casingof substantially oval cross section, an inner and an end headerproviding an expansion chamber at each end thereof, means providing aninlet and an outlet therefor, and three parallel through-flow tubesmechanically connecting the chambers and lying in a single row andhaving their axes disposed in substantially a common plane, and having amultiplicity of perforations therein, a circular intermediatetransversely split shell surrounding the center one of the tubes andtangentially engaging the side walls of the casing to provide a soundwave absorption space in the shell around the center tube and inconjunction with the outer casing a sound wave absorption space aroundeach of the other tubes, a central header tLl'ough which pass saidtubes, and which divides each of said absorption spaces in said shellinto longitudinally isolated absorption spaces, the central headerhaving a central dished portion seated within the end of one of theparts of the shell and seating the end of the other part of the shell,the inner headers being identical in shape with the central header andhaving their dished portions cooperating with the other ends of theShell parts for mutual positioning of the inner headers and the shellparts.

3. A silencer of the retroverted passage type comprising an outer casingof substantiallyoval cross section, an inner and an end header providingan expansion chamber at each end thereof, means providing an inlet andan outlet therefor, and three parallel through-now tubesmechanicallyconnecting the chambers and lying in a single row and havingtheir axes disposed in substantially a common plane, and having amultiplicity of perforations therein, a circular intermediatetransversely split shell surrounding the center one of the tubes andtangentially engaging the side walls of the casing to provide a soundwave absorption space in the shell around the center tube and inconjunction with the outer casing a sound wave absorption space aroundeach of the other tubes, a central header through which pass said tubes,and which divides each of said absorption spaces in said shell intolongitudinally isolated absorption spaces, the central header having acentral dished portion seated within the end of one of the parts of theshell and seating the end of the other part of the shell, the innerheaders being identical in shape with the central header and havingtheir dished portions cooperating with the other ends of the shell partsfor mutual positioning of the inner headers and the shell parts, the endof the shell part that seats within the central header dished portionbeing of smaller diameter'than the other shell part ends.

SIDNEY OLDBERG.

